Field of the Invention
The invention relates to a power supply technology and, more particularly, to a charging method for a portable electronic device and a portable electronic device using the same.
Description of the Related Art
As science technology develops, various portable electronic devices, such as a tablet computer, a personal digital assistant (PDA), a laptop computer and a smart phone, become necessary in daily life.
In a portable electronic device, a battery with large capacity needs longer charging time to charge. Thus, the charging efficiency needs to be improved in consideration of the battery capacity and the charging time.
A conventional battery module is first charged at a pre-charging mode when the battery module is at low power. When the power or the battery voltage is above a level, the battery module is charged at a constant current (CC) mode. When the battery voltage is nearly fully charged, the battery module is charged at a constant voltage (CV) charging mode or a trickle charging mode until the charging of the battery module is finished.
In the process of charging the portable electronic device, the CV charging mode is longer. The setting of a maximum charging voltage at the CV charging mode affects the CV charging time. Conventionally, the maximum charging voltage is preset to a constant value, which makes the charging speed of the battery module low.